The Question:

Who is the tallest person ever to have played in the NBA?

The Answer:

According to the NBA, Manute Bol and Gheorghe Muresan share that
distinction, with both standing 7'7" tall. Manute Bol played in the
NBA from 1983 to 1995 with the San Diego Clippers, Washington Bullets, and
the Golden State
Warriors. Muresan played 1993–2000 with the Washington Bullets and
New Jersey Nets, and starred in the 1998 movie My Giant with Billy
Crystal.

Some reports claim that Muresan is a few millimeters taller than
Bol, and Guinness World
Records lists only Muresan as the tallest NBA player.